Michael's auntie is 7 times as old as him. His auntie will be 47 years old in 5 years' time. In how many years' time will Michael's age be 60% that of his auntie's?
| |
Michael's auntie |
Michael |
Difference |
Before
(now) |
7x1 =
7 u |
1x1 =
1 u |
6x1 =
6 u |
| Change 1 |
+ 5 |
+ 5 |
|
| After 1 |
47 |
|
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
5x3 =
15 u |
3x3 =
9 u |
2x3 =
6 u |
60% =
60100 =
35 Michael's auntie : Michael = 5 : 3
The difference in age between Michael's auntie and Michael always remains the same. Make the difference in age between Michael's auntie and Michael the same. LCM of 6 and 2 is 6.
7 u + 5 = 47
7 u = 47 - 5
7 u = 42
1 u = 42 ÷ 7 = 6
Number of years' time when Michael's age will be 60% that of his auntie's
= 15 u - 47
= 15 x 6 - 47
= 90 - 47
= 43
Answer(s): 43
